Brother or sister for Augustin?

Hello
I have a son, named Augustin (sometimes nickname Augie) and am now pregnant with #2. We don't yet know the gender so I would like name ideas for both. I prefer not to have another name starting with A, and also don't want it to sound similar to Augustin, or start with N or D. We like unusual-ish names that are recognizable and have a more common nickname.